import java.util.*;

public class Ave3 {
    public static void main(String[] args) {
    	System.out.print("Enter the number:");
        Scanner scanner = new Scanner(System.in);
        double sum = 0;
        int count = 0;
        int number;
        while (true) {
            try {
                number = scanner.nextInt();
                if (number == -1) {
                    break;
                }
                sum += number;
                count++;
            } catch (InputMismatchException ex) {
                System.out.printf("pass the non-integral number：%s%n", scanner.next());
            }
        }
        System.out.printf("Ave %.2f%n", sum / count);
    }
}
